Overview of the X-SAR / SRTM Data Processing and Scientific Investigations

Kurzfassung

In February 2000, the Shuttle Radar Topography Mission (SRTM) successfully mapped the entire landmass between 60 N and 54 S using the NASA/JPL C-band and the DLR X-band Interferometric Synthetic Aperture Radar Systems. The data acquired were independently processed to Digital Elevation Models (DEM) by NASA-JPL (C-band) and DLR (X-band). A commonly used source was the Position and Attitude Determination Record (PADR) generated by the Attitude Orbit Determination Avionics (AODA) system. The PADR file provided the orbit and baseline information. All X-band data were systematically processed to 1 arc-second resolution DEMs according to DTED-2 specification and cover a grid with 50 km swath width equal to about 60 Million square kilometers on the earth. Processing was finished in summer 2004 and all the X-band DEMs are available via DLR’s German Remote Sensing Data Center (DFD). Principal investigators from all over the world have received more than 1000 image and DEM products from the X-SAR/SRTM data set to perform their proposed experiments and evaluations. Test areas in Europe, Africa, North and South America, Australia and Asia have been used. The major application was to validate the data set and to compare it with other DEM data sources and with the C-band data. There are also investigations about the use in geophysical applications like hydrology, oceanography, geology and forestry but also for archeology, disaster prevention, navigation and traffic monitoring. This paper presents an overview of the X-Band data processing and results of the scientific use of X-band data elaborated by the PI team. Results reported so far, are indicating that the ambitious mission has performed as expected and the performance achieved fulfills the specifications. The mayor drawback for a broad use is the gaps in the X-SAR/SRTM data set.